CLYDESDALE TRIATHLON: WEIGHT RULES, FUELING AND TRAINING FOR HEAVIER TRIATHLETES

In triathlon, Clydesdale is the weight category for men who weigh 220 pounds or more, and Athena is the category for women 165 pounds or more. USA Triathlon lets sanctioned races offer both. This guide covers the weight rules, what the research says about heavier triathletes (less than you'd think), and how The Clydesdale Protocol adjusts fueling, hydration, training and gear for a bigger body.

Where I'm coming from: I race as a Clydesdale. I've done more than 300 races, including four Ironman finishes, and at 60 I qualified for USA Triathlon Nationals. I'm not a physician or a coach. Below, I keep what the studies measured separate from what my book recommends.

Clydesdale Triathlon Weight Rules

• The minimums. At USA Triathlon's National Championships the minimums are 220 pounds for Clydesdale men and 165 pounds for Athena women, checked at an official weigh-in.
• Age splits. Clydesdales race in 39 and under, 40–59 and 60 and over. Athenas race in 39 and under, 40–54 and 55 and over.
• You keep your age group. You stay in your regular age group too. Only age-group results count toward qualifying for Nationals.
• Local races vary. Some don't offer the categories. Some use other cutoffs (200 and 150 pounds turn up). Some skip the weigh-in. Check your race's own rules before you register.

What the Research Says About Heavier Triathletes

I searched PubMed for studies of Clydesdale or Athena triathletes and found none. As a check, the same search for "triathlon" returns more than 1,400 studies. The closest research is in runners, and it doesn't all point one way:

• Energy per mile. In a lab study of men running at 8 km/h (Taboga 2012), the energy cost of running per kilogram of body weight was the same for severely obese and normal-weight runners. So total energy per mile scales roughly with body weight: at 240 pounds you use about 55% more per mile than at 155 pounds, by simple proportion.
• Impact. In Vincent's 2020 lab study, runners with obesity had higher total impact per stride and higher hip loading. Impact scaled to body weight was higher in the lighter runners, and the heavier runners took shorter, stiffer, flatter strides.
• Knee injuries. In 2,612 runners pooled from four studies (Juhler 2020), knee injuries made up a smaller share of all injuries among overweight and obese runners than among normal-weight runners. That's the share of injuries that were knee injuries, not the overall chance of getting hurt.

Fueling: The Hourly Target Doesn't Change With Your Weight

This surprises many heavier athletes. Jeukendrup's 2014 review of carbohydrate during exercise sets the targets by how long the event lasts:

• About 60 grams an hour for events of 2 to 3 hours.
• About 90 grams an hour for ultra-endurance events, which requires a mix of carbohydrate types (glucose and fructose, for example) so the gut can absorb that much.

The review states that this advice is independent of body weight. What does scale with weight is your total daily energy use on training days (see energy per mile above). That gap is where the book puts the emphasis: eat enough across the whole day, and save weight loss for the off-season instead of a heavy training block.

Two other numbers come up often:

• Protein. In Morton's 2018 meta-analysis of 49 trials in healthy adults doing resistance training, protein above about 1.6 grams per kilogram a day added no further gain in lean mass.
• Caffeine. The International Society of Sports Nutrition's 2021 position stand reports benefits at 3 to 6 mg per kilogram of body weight, with endurance the most consistent. Several of its authors disclose supplement-industry ties. Ask your physician before using caffeine this way, especially if you have a heart condition or high blood pressure.

Sweat and Sodium: Measure, Don't Guess

The American College of Sports Medicine's fluid position stand says sweat rates and sweat sodium vary so much between people that fluid plans should be individual. Baker's 2017 review names body size as one of the factors behind that variation.

A larger 2022 analysis by Baker's group covered 1,944 sweat tests. Energy expenditure and season were the strongest predictors of sweat sodium, and body mass had a small effect. All the factors together explained only 17% to 23% of the variation. In other words, you can't predict your own number from your weight. The authors work for PepsiCo, which makes Gatorade.

The test both reviews describe is simple:

1. Weigh yourself nude before an hour at race effort.
2. Note everything you drink.
3. Weigh yourself again afterward. Each kilogram lost, plus what you drank, is about a liter of sweat.
4. Repeat on a cool day and a hot one, since the number changes with conditions.

White salt marks on your clothes after a long session are a common sign of salty sweat. A lab sweat test gives you the actual sodium number.